The present invention relates generally to tracheostomy tubes, and more specifically tracheostomy tubes that provide a means to prevent a patient from aspirating secretions, food or fluid while a tracheostomy tube is in use.
The normal structure and function of the aero-digestive tract, including the mouth and pharynx, bounded inferiorly by the larynx, serve to protect the airway by preventing secretions, fluid and/or food from entering the laryngeal space and thereby compromising the airway. When airway protection is ineffective or inefficient, secretions, fluids and/or food may enter the trachea via the true vocal cords and eventually move into the lungs. Any secretion, fluid or food that bypasses normal airway protection and enters beyond the level of the vocal cords is, by definition, aspiration. Various management techniques are available to minimize or prevent aspiration. These include the restriction or cessation of an oral diet and/or the use of compensatory techniques that allow the patient to exert conscious control over the physiological mechanisms of airway protection. For individuals with tracheostomies, aspiration may also be prevented or minimized through the use of artificial airway protection.
Artificial airway protection may be provided through the use of cuffed tracheostomy (trach) tubes or laryngeal stents. Cuffed trach tubes are similar to traditional, cuffless trach tubes, which are basically curved plastic tubes, which provide a passageway for air to the lungs. However, a cuffed trach tube has an inflatable flexible balloon-like cuff attached to the external surface of the distal end of the trach tube. When inflated, the cuff expands to fill the lumen of the trachea. The main purpose of the cuff is to maximize ventilation of the lower airway by preventing the escape of gas (air) via the upper airway. In addition, the inflatable cuff design may temporarily prevent aspirated material from reaching the lungs. However, once the cuff is deflated, aspirated material that remains on top of the cuff is acted upon by gravity and travels downward toward the lung. Thus, the cuffed trach tube does not prevent aspiration, but only delays the aspirated material from reaching the lungs. Moreover, continuous inflation of the cuff may lead to other problems (for example, irritation to the surrounding tissue with prolonged placement of the cuff and/or the colonization of bacteria in the trachea due to inaccessibility of the cuff for cleaning).
Traditional laryngeal stents, another artificial means of aspiration prevention, require a medical procedure to place a physical block within the larynx. Stents are typically used to support tissue grafts and to block off flow through the trachea while the larynx is being reconstructed. Traditional stents are sutured in place, and removal can be quite traumatic. Although stents have proven somewhat effective, they have a very limited application and an unfavorable cost-to-benefit ratio due to the possible complications during placement and subsequent side effects. Moreover, when a traditional laryngeal stent is in place, an individual is not capable of speaking.
Improvements of traditional laryngeal stents have occurred, such as the ones shown in U.S. Pat. No. 5,494,029 issued Feb. 27, 1996 and U.S. Pat. No. 4,794,924 issued Jan. 3, 1989. Both of these stents are inflatable and flexible, with dimensions and configurations which allow the stent to be positioned adjacent to the larynx to contact and support anatomical features in the glottic and supraglottic region of the larynx. The diameter of the stent once inflated is such as to provide a seal above the larynx; thus, it is capable of delaying aspiration. Additionally, the '924 patent includes a unidirectional valve-like arrangement on the rounded upper surface of the stent which allows for venting of pressure from below the larynx, such as when the patient coughs; however, when the patient inhales, the flaps of the valve-like arrangement are drawn together in a closed position. Thus, with both of these devices, once the stent is deflated, any fluid or particulate accumulated on top of the stent is acted upon by gravity and travels downward toward the lungs.
To date, there is no readily available effective method of aspiration management for tracheostomized patients. The tracheostomy aspiration suction tube (TAST) described below provides for an effective means of managing aspiration in tracheostomized patients. The TAST is designed for individuals who require the placement of a tracheostomy tube and who present with difficulty swallowing or dysphagia that results in aspiration. The TAST collects and drains the aspirated material from the trachea, thus preventing it from entering the lower airway where it may lead to respiratory complications. Additionally, the TAST provides a means to remove and clean the collection receptacle and drainage tube used to collect and remove the aspirated material.